Rotary forge furnace



Dc. y24, 1946. w. M'. HEPBURN ET AL 2,413,228.

ROTARY FORGE FURNACE Filed Aug. 9, 1944 2 Sheets-Sheet l Snventor WM. Hwuzu. W.O OWEN.

" (Itter-neg Dec. 24, 1946. w. HEPURN ETAL 2,413,228

ROTARY FORGE FURNCEI Filed Aug. 9, l1944 '2 SheetsfSheet 2 Fie-5 Mdm Gttorneg Patented Dec. 24,` 1946 ROTARY FORGE FURNACE William M. Hepburn, Ottawa Hills, Ohio, and William O. Owen, Evanston, Ill., assignors to Surface Combustion Corporation, Toledo, Ohio, a corporation of Ohio Application August 9, 1944, Serial No. 548,762

7 Claims.

The present invention relates to a combustionheated rotary forge furnace for heating articles to forging temperature in a protective atmosphere and has for its object to provide an improved furnace of this type.

For a consideration of what is believed to be novel and our invention attention is directed to the following specification and the claims appended thereto.

in the accompanying drawings:

Fig. 1 is a vertical section through a rotary furnace embodying the present invention.

Fig. 2 is a reduced partial plan and horizontal section of the furnace shown in Fig. l,

Fig. 3 is an enlarged vertical section of parts embodied in the furnace shown in Fig. 1.

Fig. 4 is a fragmentary vertical cross section of parts in Fig. 3.

Fig. 5 is a front elevation and Fig. 6 is a partial side elevation and vertical section of door operating mechanism embodied in the furnace shown in Fig. l.

Fig. 7 is an enlarged horizontal cross section of parts of the door operating mechanism.

Figs. 8 to l0 are fragmentary detail views of parts embodied in the furnace shown in Fig. l.

The improved furnace comprises a plurality of relatively elongated retorts or muflies IB horizontally disposed about a vertical axis on a rotary support or platform il mounted for rotation about said axis by any preferred means shown as comprising a circular track I2 secured to the underside of the platform and supported on rollers I3 mounted on a foundation base I4. The platform is power driven by any preferred means shown as comprising a ring gear I5 or the like secured t0 the underside of the platform.

The platform constitutes the -bottom of a combustion chamber heated by burners in burner ports it. It is not essential that the upper half of the combustion chamber should rotate with the lower half and, therefore, to this end the upper half is made stationary and is comprised of a bell I8 having a flat roof I and a depending circular side wall 2@ which terminates short of an upstanding circular side wall 2i constituting part of the platform Ii.

The bell I8 is supported from above by a plurality of hangers 22 secured to side Wall of the bell and extending upwardly to an overhead supportV 23 which in turn is supported on pedestals 2d extending upwardly from the fixed foundation of the furnace. To prevent undue leakage of combustion gases from the combustion chamber at the joint between the upper and lower halves of said chamber, a peripheral liquid seal is provided at said joint, the seal being comprised of a circumferential trough 26 secured to the platform Wall 2l and a circumferential flange 21 secured to the bell wall 2t for dipping into the trough 26. The lower edge of the bell wall 20 will ordinarily be Water cooled by a cooling ring 28 embedded therein.

The retorts il] are preferably but not necessarily so mounted on the platform Il that the heating gases in the combustion chamber in order to pass out of said chamber must first flow under the retorts and thence into the foot of an upright exhaust flue 2S mounted on the platform II and from which they pass to Waste by way of a communicating flue passage 30 in the roof of the bell I8. The flue passage beneath each retort is in.- dicated at 3l, and the gas entrance to this passage at 32.

At their inner ends the retorts II) are disposed against an abutment 36 from which they extend forwardly to and through radial apertures in the upstanding side wall 2I of the platform II. Between said abutment and said apertures the retort,s are supported on saddles 38, and in said apertures they are surrounded by asbestos rope packing yi. The retorts must be able to withstand a forging temperature of 2300 F. and, therefore, are made of a non-metallic refractory V30 material such as silicon carbide (Carborundum) which has a high thermal conductivity (for a non-metallic refractory) and which retains great strength to compressive loads at elevated temperatures. The retorts are built up of circular 35 sections 40 arranged end to end in abutting re- 40 gas-tight at its joints.

lation and an end closure 4I. A yieldable compressive force is is applied to the outer end of the retort to hold the sections thereof in abutting relation so as to maintain the retort reasonably This compressive force is applied by a plurality of springs 43 which press against a sleeve-type metal frame 42 which in turn presses Vagainst the outer end of the retort, the springs being held in place by bolts 44 car- 45 ried by brackets 48 secured to the metal casing 3 walls with arcuate bottoms for proper seating in the retort. The end walls of the stools are apertured or notched as at 53 so that a work-protecting atmosphere, such as nitrogen, from a feed chamber 55 at the lower front end of the retort may flow beneath the hearth to the rear end of the retort and thence upwardly whereby to insure proper distribution of the atmosphere throughout the retort. The atmosphere is supplied to the chamber 55 by an upright pipe 54 which constitutes part of a pipe 5B which leads from a supply chamber 51 co-axial with the platform I I therebelow. The main supply pipe leading to this chamber 51 is indicated at 58.

When a retort is at the charging station it is desirable to provide for a greater inflow of protective atmosphere than is normally required once the retort has been thoroughly purged of air. To this end the pipe 54 is provided with a flapper type valve B0 which when opened permits increased flow of protective atmosphere tothe retort. To open the valve, the flapper has a downwardly extending operating arm 6I, the free end of which carries a roller 64. Normally the center of gravity through the arm and roller is such as to hold the flapper in closed position. One or more bleed holes 63 in the ilapper permits a minimum flow through the valve when the flapper is in closed position. To turn the ilapper to open position there is provided in the path of the roller 64 a cam track '62 having at its front end an incline up which the roller must ride. The track is long enough to hold the valve open for some time after the retorts move away from charging position.

The charging station is indicated at 65 and the discharging station at 61, it being understood that the rotation of the platform on which the retorts are suported is clockwise as viewed in Fig. 2. At the charging station is a door operating means 66 and at the discharging station is an identical means 6B. This door operating means comprises an elevator 58 adapted to be actuated by means under the control of the operator. The elevator comprises a cross head 69 (see Fig. 5) confined to vertical movement by vertical guide Ways 1I.

'On top of the cross head is a saddle 12 adapted to interengage with an overhead cross bar 13 carried by rigid arms 14 depending from the door 45. The door is supported by means 46 comprising axially alined journal pins 15 at the lateral sides of the door, these pins extending into a cam slot 18 in guide plates 11 carried by the spring pressed frame 42. The cam slot comprises an upper inverted V-shape portion 1I) for guiding f:-

the door into wedging position against the outer face of the spring pressed frame 42. It will, therefore, be understood that to open the door it is first moved upwardly and then downwardly by the elevator means and that the reverse movement will close the door. When the weight of the door is taken by the saddle 12 the door can fulcrum about its cross bar 13 and the guide'pins 15 can, therefore, pass from one leg to the other f and removed therefrom at the station immediately preceding the loading station.

The use of a plurality of relatively small individual retorts mounted for turning in unison about a common vertical axis in a common combustion chamber makes it unnecessary to shut down the furnace formmedaite repairs simply because one retort may be in need of repairs and, of course, makes it possible to adjust the individual atmosphere requirements of each retort to maintain a protective atmosphere about the work therein. p Moreover, by maintaining the retorts under compression, it becomes practical to employ preformed readily replaceable sections of heat conducting non-metallic refractory in the construction of the retorts.

By supporting the closure doors for the retorts in a manner permitting the use of power operated door operating means at the loading and unloading stations for opening and closing the doors, the loading and unloading operations can proceed with minimum delay.

The provision of means for automtaically increasing the flow of protective atmosphere to a retort that has just been loaded reduces to a minimum the danger of damage to the work by oxidation immediately following loading.

Other advantages of the present invention will be apparent to those skilled in the art. The apparatus is relatively simple and is easily kept in repair.

What is claimed as new is:

1. A rotary furnace comprising, in combina- Y tion, a support mounted to turn about a vertical axis and having an upstanding peripheral wall, a plurality of retorts mounted on said support for rotation therewith and each having an access door at the outer side of said wall, means comprising said support and its upstanding wall forming a combustion chamber about said retorts for heating the retorts to heat the articles therein to elevated temperature, a station where the articles to be heated are placed in the retorts and another station where the heated articles are removed from the retorts, and means for conducting anarticle protecting atmosphere to said retorts during their course of travel about said vertical axis.

2. A rotary furnace comprising, in combination, a support mounted to turn about a vertical axis and having an upstanding peripheral wall, a plurality of retorts mounted on said support for rotation therewith and each having an access door at the outer side of said wall, means comprising said support and its upstanding wall forming a combustion chamber about said retorts for heating the retorts to heat the articles therein to elevated temperature, a station where the articles to be heated are placed in the retorts and another station Where the heated articles are removed from the retorts, and means at said stations for opening and closing the doors of the retorts on their arrival at said stations.

3. A rotary furnace comprising, in combination, a support mounted to turn about a vertical axis and having an upstanding peripheral Wall, a plurality of retorts mounted on said support for rotation therewith and each having an access door at the outer side of said wall, means comprising said support and its upstanding Wall forming a combustion chamber about said retorts for heating the retorts to heat the articles therein to elevated temperature, a station Where the articles to be heated are placed in the retorts and another station where the heated articles are removed from the retorts, and means for conducting an article protecting atmosphere to said retorts during their course of travel about said vertical axis, said retorts comprising individual sections arranged end to end, and means for maintaining the retorts under longitudinal compression to maintain them relatively gastight at their joints.

4. A rotary furnace comprising, in combination, a support mounted to turn about a vertical axis and having an upstanding peripheral wall, a plurality of retorts mounted on said support for rotation therewith and each having an access door at the'outer side of said wall, means comprising said support and its upstanding wall forming a combustion chamber about said retorts for heating the retorts to heat the articles therein to elevated temperature, said wall having apertures wherein the outer end of the retorts are slidably positioned to allow for longitudinal expansion and contraction of the retorts, and means carried by said wall for yieldably pressing against the outer end of the retorts to maintain the retorts under longitudinal compression.

5. A rotary furnace comprising, in combination, a support mounted to turn about a vertical axis and having an upstanding peripheral wall, a plurality of retorts mounted on said support for rotation therewith and each having an access door at the outer side of said wall, means comprising said support and its upstanding Wall forming a combustion chamber about said retorts for heating the retorts to heat the articles therein to elevated temperature, said retorts being circular in cross section, and means providing a at hearth in the retorts.

6. A rotary furnace comprising, in combination, a support mounted to turn about a vertical axis and having an upstanding peripheral wall, a plurality of retorts mounted on said support for rotation therewith and each having an access door at the outer side of said Wall, means comprising said support and its upstanding wall forming a combustion chamber about said re'- torts for heating the retorts to heat the articles therein to elevated temperature, a station Where the articles to be heated are placed in the retorts and another station where the heated articles are removed from the retorts, means for conducting an article protecting atmosphere to said retorts during their course of travel about said vertical axis, and means for temporarily increasing the input of said atmosphere to a retort following the charging thereof with articles to be heated.

7. A rotary furnace comprising, in combination, a support mounted for rotation about a vertical axis and having an upstanding peripheral wall, a plurality of cylindrical retorts mounted on said support and extending radially outward into individual apertures in said wall for rotation therewith, means comprising said support andl its upstanding peripheral wall forming a combustion chamber about said retorts for heating them to heat the articles therein to elevated temperature, a sleeve means in said apertures to abut the adjacent end of the retort, means for yieldably pressing said sleeve means against the said end of the retort, and a door carried by said sleeve means for closing the access opening to the retort.

WILLIAM M. HEPBURN. WILLIAM O. OWEN. 

